This application is based on and claims priority of Japanese Patent Applications of Nos. Hei. 8-266376 filed on Oct. 7, 1996, Hei. 8-287016, filed on Oct. 29, 1996, Hei. 8-343410 filed on Dec. 24, 1996, and Hei. 9-91003 filed on Apr. 9, 1997, the contents of which are incorporated herein by reference.
1. Field of the Invention
This invention relates to an air conditioning apparatus, in which a passage of conditioned air is partitioned into a first air passage at a side of inside air and a second air passage at a side of outside air. A high-temperature inside air having been heated re-circulates and is blown out from a foot air outlet, and outside air having a low-humidity is blown out from a defroster air outlet, to improve a heating capacity and to defrost a windshield.
2. Description of Related Art
In a conventional air conditioning apparatus as disclosed in JP-A-5-124426, there are formed at one end side of an air conditioning case an inside-air inlet for introducing inside air and an outside-air inlet for introducing outside air and at the other end side of the air conditioning case a foot air outlet for blowing air toward a foot area, a defroster air outlet for blowing air toward an inner surface of a windshield, and a face air outlet for blowing air toward a face area.
In the air conditioning case, there is provided a partition plate for partitioning an interior of the air conditioning case into a first air passage extending from the outside-air suction port to the face air outlet and the foot air outlet and a second air passage extending from the outside-air suction port to the defroster air outlet.
Further, in each of the first and the second air passages, there are provided a heating heat exchanger, a bypass passage bypassing the heating heat exchanger, and an air mixing door. The air mixing door includes a door at a side of the first air passage, and another door at a side of the second air passage, which are integrally provided with a single rotary shaft rotatably disposed over both air passages.
When any one of the face mode, the bi-level mode, and the foot mode is selected as air outlet mode, if the inside air/outside air introduction mode is set to the inside-air circulation mode, the inside air is introduced into both air passages, whereas if the mode is set to the outside-air introduction mode, the outside air is introduced into both air passages.
Further, when the foot/defroster mode is selected as the air outlet mode, there is set an inside air/outside air double laminar mode in which the inside air is introduced into the first air passage and the outside air is introduced into the second air passage. In this way, because a passenger compartment is heated by a recirculation of the inside air which has been already heated, the heating performance is improved. Further, because the outside air having a low humidity is blown toward the windshield, it is possible to secure the defrosting performance of the windshield certainly.
In recent years, as for an air conditioning apparatus for a vehicle, in view of a limited space for being mounted on a vehicle as well as a cost reduction, a compactness of an air conditioning unit mounted on a vehicle and a simplicity of the construction have become significant problems. In the above-described prior art, it is necessary to additionally provide the partition plate for partitioning the first air passage and the second air passage in addition to the general construction elements of the air conditioning unit. As a result, the construction is complicated, the cost increases, and the air conditioning unit is large-sized to avoid an interference of the partition plate and the door members.
In view of the above-described problem, an object of the present invention is to downsize an air conditioning unit and to simplify a construction thereof, in the air conditioning apparatus for a vehicle, in which there is set a double laminar mode for partitioning inside air and outside air in an air conditioning case.
According to a first aspect of the present invention, in an air outlet mode where both of a first opening portion for blowing air toward a lower portion of a passenger compartment and a second opening portion for blowing air toward an inner surface of a windshield are opened, when the maximum heating state is set, an air passage is partitioned into a first air passage through which inside air flows and a second air passage through which outside air flows, in such a manner that the first air passage is communicated with the first opening portion, the second air passage is communicated with the second opening portion. Further, there are formed a first warm air passage for introducing the warm air having passed through a heating heat exchanger into the first and the second air opening portions and a second warm air passage for introducing the warm air having passed through the heating heat exchanger directly into the first air opening portion while bypassing the first warm air passage. An inlet portion of the second warm air passage is opened and closed by the warm air bypass door. In a double laminar mode where the first air passage and the second air passage are partitioned, the warm air bypass door is operated to a position where the inlet portion is opened and the warm air passage is partitioned into the first air passage and the second air passage.
In this way, because the warm air bypass door itself functions as a movable partition member for partitioning the inside air and the outside air, a space for providing a stationary partition member can be reduced, so that an air conditioning unit can be downsized, and a construction thereof can be simplified.
According to a second aspect of the present invention, as an air mixing door for adjusting a ratio of an amount of air passing through a heating heat exchanger and an amount of air passing through a cool air bypass passage, there are provided a main air mixing door and an auxiliary air mixing door, both of which are disposed at an air upstream side of the heating heat exchanger and operated with each other. Further, in a double laminar mode where a first air passage and a second air passage are partitioned, the main air mixing door fully closes the cool air bypass passage, and the auxiliary air mixing door partitions a space at an air upstream side of the heating heat exchanger into the first air passage and the second air passage.
In this way, because the air mixing door itself functions as a movable partition member for partitioning the inside air and the outside air, a space for providing a stationary partition member can be reduced. Further, a space for rotating two air mixing doors can be commonly used. Therefore, an air conditioning unit can be downsized, and a construction thereof can be simplified.